Growth Hormone, 90 Minutes

Casandra

Casandra Test Code AR52122Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 0070084CPT Code 83003

Growth Hormone, 90 Minutes

Also known as: GH 90

Clinical Use

Order Test

Use

For pediatric patients, very low peak growth hormone (GH) concentrations on stimulation testing are consistent with severe GH deficiency (GHD). Thresholds distinguishing normal from partial GHD have not been well established. Inadequate response to two different provocative tests is required for diagnosis of GHD. In adults, expected peak GH concentrations depend on the stimulation test performed, as described in Endocrine Society guidelines for the evaluation and treatment of adults with GHD. For suppression testing, healthy subjects have GH concentrations of less than 1 ng/mL within 2 hours of ingestion of a 75 or 100 gram glucose dose. Patients with acromegaly fail to show normal suppression.

Special Instructions

This Growth Hormone assay is standardized to the Recombinant Second International Standard (IS): 98/574. Growth hormone results read approximately 25 percent lower than with the previous standards (First IS: 80/505). Reference ranges have also been modified according to the assay manufacturer.

Limitations

Thresholds distinguishing normal from partial Growth Hormone Deficiency (GHD) have not been well established. The assay shows approximately 25 percent lower readings compared to previous standards, which may affect the interpretation of results based on historical reference ranges. It is important to use adequate calibration and controls based on the current standardization.

Test Details

New York Approved

Methodology

Immunoassay (CLIA)

Biomarkers

Growth Hormone

Analyte

Growth Hormone 90 Minutes • Concentration / Level • Quantitative (Continuous) (e.g., copies/mL, % expression)

LOINC Codes

Result Codes

14147-3

Result Turnaround Time

1-2 days

Specimen

Plasma

Volume

1 mL

Minimum Volume

0.4 mL

Container

Plasma separator tube or serum separator tube

Collection Instructions

Collect one tube per timed specimen. Allow specimen to clot completely at room temperature. Separate serum or plasma from cells ASAP or within 2 hours of collection. Transfer to individual ARUP Standard Transport Tubes.